A Facile Synthesis ofN-(4-Aryl-1,3-dithiol-2-ylidene)-amides,N-(4- or 5-Aryl-1,3-thiaselenol-2-ylidene)-amides, andN-(4-Aryl-1,3-diselenol-2-ylidene)-amides

Isoselenocyanates: a powerful tool for the synthesis of selenium-containing heterocycles

Selenium-containing heterocyclic compounds have been well recognized, not only because of their remarkable reactivities and chemical properties, but also because of their diverse pharmaceutical applications. In this context, isoselenocyanates have been emerged as a powerful tool for the synthesis of selenium-containing heterocycles, since they are easy to prepare and store and are safe to handle. In this review the recent advances in the development of synthesis methods for selenium-containing heterocycles from isoselenocyanates are presented and discussed.

Synthesis of Alkynechalcogenolato Complexes of Titanocene(IV) and Samarocene(III) and Formation of a Ti(2)Ni Trinuclear Cluster [Cp(2)Ti(&mgr;-SC&tbd1;CPh)(2)](2)Ni

Reactions between (C(5)H(4)R')(2)TiCl(2) and 2 equiv of LiEC&tbd1;CR generated a series of alkynethiolato and alkyneselenolato complexes of titanocene(IV), (C(5)H(4)R')(2)Ti(EC&tbd1;CR)(2) in high yields (1, R = Ph, R' = H, E = S; 2, R = p-C(6)H(4)CH(3), R' = H, E = S; 3, R = (t)Bu, R' = H, E = S; 4, R = Ph, R' = Me, E = S; 5, R = Ph, R' = H, E = Se). Complex 1 reacted with (1)/(2) equiv of Ni(cod)(2) to give a linear Ti(2)Ni trimetallic complex, [Cp(2)Ti(&mgr;-SC&tbd1;CPh)(2)](2)Ni (6), in which the Ni atom links two Cp(2)Ti(SC&tbd1;CPh)(2) units through interactions with thiolate sulfur bridges. Treatment of Cp(2)Sm(&mgr;-Cl)(2)Li(OEt(2))(2) with 2 equiv of LiSC&tbd1;CPh and TMEDA resulted in [Li(tmeda)(2)][Cp(2)Sm(SC&tbd1;CPh)(2)] (7). The structures of complexes 4, 5, 6, and 7 were determined by X-ray diffraction analysis.